Myositis specific antibodies are associated with isolated anti-Ro-52 associated interstitial lung disease

Review of Pulmonary Manifestations in Antisynthetase Syndrome

Antisynthetase syndrome (ASyS) is now a widely recognized entity within the spectrum of idiopathic inflammatory myopathies. Initially described in patients with a triad of myositis, arthritis, and interstitial lung disease (ILD), its presentation can be diverse. Additional common symptoms experienced by patients with ASyS include Raynaud's phenomenon, mechanic's hand, and fever. Although there is a significant overlap with polymyositis and dermatomyositis, the key distinction lies in the presence of antisynthetase antibodies (ASAs). Up to 10 ASAs have been identified to correlate with a presentation of ASyS, each having manifestations that may slightly differ from others. Despite the proposal of three classification criteria to aid diagnosis, the heterogeneous nature of patient presentations poses challenges. ILD confers a significant burden in patients with ASyS, sometimes manifesting in isolation. Notably, ILD is also often the initial presentation of ASyS, requiring pulmonologists to remain vigilant for an accurate diagnosis. This article will comprehensively review the various aspects of ASyS, including disease presentation, diagnosis, management, and clinical course, with a primary focus on its pulmonary manifestations.

A Review of Antisynthetase Syndrome-Associated Interstitial Lung Disease

Our objective in this review article is to present a clinical case of a patient with antisynthetase syndrome (ASyS) and provide an overview of the pathogenesis, classification criteria, antibody profiles, clinical features, and current knowledge of treatment options, focusing on interstitial lung disease (ILD). ASyS is an uncommon autoimmune disease with a heterogenous clinical presentation characterized by the presence of autoantibodies against an aminoacyl-tRNA synthetase and manifested by myositis, fever, inflammatory arthritis, Raynaud's phenomenon, mechanics hands, and ILD. ASyS-associated ILD (ASyS-ILD) is the most serious complication of ASyS, which may evolve to rapidly progressive ILD; therefore, it often requires thorough clinical and radiologic evaluation including recognition of a specific clinical phenotype associated with the antisynthetase antibodies (ASAbs) to guide therapeutic interventions.

Antibodies against Small Ubiquitin-like Modifier Activating Enzyme May Be a Protective Factor from Rapid Progressive Interstitial Lung Disease in Patients Bearing Antibodies against Melanoma Differentiation Associated Gene 5

Background: Anti-MDA5 antibody-bearing (anti-MDA5+)-dermatomyositis (DM) or polymyositis (PM) is notorious for causing rapidly progressive interstitial lung disease (RPILD) and/or cancers with high mortality rate. However, anti-MDA5 antibodies (Abs) are also found in other connective tissue diseases and their link with RPILD, especially with regard to the mortality rate, are unknown. Methods: We retrospectively recruited 71 patients bearing anti-MDA5-Abs in serum, stratified them in terms of a presence or absence of RPILD, and evaluated their clinical features, laboratory findings, associated myositis antibodies, concurrent connective tissue disease (CTD) as well as newly developed malignancies. Results: In total, 39 (55%) patients presented with DM/PM, but 32 (45%) did not. In total, 22 of the former and 11 of the latter developed RPILD eventually, accounting for a total of 46% of all MDA-5 bearing patients. On the other hand, 15 of all 71 (21.1%) patients had cancers. Among the 32 patients who did not have DM/PM, 27 (38.0% of all 71) had other CTDs, indicating that only 5 (7.0% of 71) patients did not have CTDs. Senility (odds ratio (OR) = 1.816, p = 0.032), presence of anti-Ro-52 antibody (OR = 1.676, p = 0.018), elevated C-reactive protein (CRP, OR = 4.354, p < 0.001) and carcinoembryonic antigen (CEA, OR = 2.625, p = 0.005) posed risks for RPILD. High lactose dehydrogenase (LDH, p = 0.009), CRP (p = 0.001) and CEA (p = 0.001), ferritin (p ≤ 0.001) and low albumin (p ≤ 0.001) were significantly associated with mortality. Anti-SAE antibodies were negatively correlated with RPILD as analyzed by univariate (OR = 0.245, p = 0.017) and multivariate (OR = 0.058, p = 0.036) regressions, indicating that they may be a protective factor in relation to RPILD (OR = 0.543, p = 0.008) or fatality (OR = 0.707, p = 0.012), which was also demonstrated in subgroup analyses. Conclusions: In contrast to various risk factors for RPILD or mortality, anti-SAE antibodies might conversely be a protective factor in anti-MDA5+ patients.

Dissociating Autoantibody Responses against Ro52 Antigen in Patients with Anti-Synthetase or Anti-MDA5 Antibodies

We aimed to dissociate the autoantibody response against the Ro52 protein in patients with anti-synthetase or anti-melanoma differentiation-associated gene 5 (MDA5) antibodies to explore the potential roles of different anti-Ro52 autoantibody responses in disease subclassification. This study used a single-center, prospective myositis cohort involving 122 consecutive patients with anti-synthetase antibodies identified by RNA immunoprecipitation (RNA-IP) and 34 patients with anti-MDA5 antibodies detected using enzyme immunoassay (EIA). Anti-Ro52 antibodies were measured using commercial EIA kits, while anti-Ro/SSA antibodies were identified using RNA-IP. Clinical features and outcomes were stratified according to two different patterns of autoantibody responses against Ro52, including "isolated anti-Ro52", defined by positive anti-Ro52 and negative anti-Ro/SSA antibodies, and "anti-SSA-Ro52", defined by positive anti-Ro52 and anti-Ro/SSA antibodies. Isolated anti-Ro52 positivity was the most prevalent autoantibody response in patients with both anti-synthetase (40/122; 32.8%) and anti-MDA5 antibodies (8/34; 23.5%). Isolated anti-Ro52 or anti-SSA-Ro52 positivity was associated with Gottron's sign in patients with anti-synthetase antibodies, while in patients with anti-MDA5 antibodies, isolated anti-Ro52 positivity was associated with respiratory insufficiency at initial presentation and poor overall survival. Isolated anti-Ro52 positivity could be a potential biomarker for patient stratification; however, the clinical significance of dissociating isolated anti-Ro52 positivity from overall anti-Ro52 positivity was not evident.

Myositis interstitial lung disease and autoantibodies

The aim of this review is to examine and evaluate published literature associated with idiopathic inflammatory myopathies (IIM) and interstitial lung disease (ILD) based on myositis specific autoantibodies (MSA) and the potential clinical significance of each autoantibody subtype for the practicing clinician. The review is a comprehensive search of literature published in PubMed from the year 2005 and onward coinciding with the surge in the discovery of new MSAs. Additionally, we comment on recommended multidisciplinary longitudinal care practices for patients with IIM-ILD with regard to imaging and other testing. Treatment is not covered in this review.

Clinical, radiological and pathological features of anti-MDA5 antibody-associated interstitial lung disease

INTRODUCTION

To investigate the clinical, radiographic and pathological features of interstitial lung disease (ILD) in patients with anti-melanoma differentiation-associated gene 5 antibody-positive dermatomyositis (anti-MDA5+DM).

METHODS

We retrospectively analysed the medical records of patients with anti-MDA5+DM who had undergone radiological examination, and lung histopathology was performed on 17 of them.

RESULTS

This study examined 329 patients with anti-MDA5+DM, of whom 308 (93.6%) were diagnosed with ILD and 177 (53.8%) exhibited rapidly progressive ILD (RPILD). The most common radiographic patterns were organising pneumonia (OP) (43.2%), non-specific interstitial pneumonia (NSIP) (26.4%) and NSIP+OP (18.5%). Histological analysis showed NSIP (41.2%) and NSIP+OP (47.1%) to be the predominant patterns. However, in the 17 patients who underwent lung histopathology, the coincidence rate between radiological and histopathological diagnoses was only 11.8%. Compared with patients without RPILD, those with RPILD showed a higher prevalence of NSIP+OP (26.6% vs 10.7%, p=0.001) and a lower prevalence of NSIP pattern (21.5% vs 37.4%, p=0.002) on high-resolution CT. Furthermore, patients with radiographic patterns of NSIP+OP or diffuse alveolar damage (DAD) had more risk factors for poor prognosis, with 12-month mortality rates of 45.9% and 100%, respectively.

CONCLUSIONS

RPILD was commonly observed in patients with anti-MDA5+DM. OP was identified as the predominant radiographic pattern, which corresponded to a histopathological pattern of NSIP or NSIP+OP. Notably, patients exhibiting radiographic patterns of NSIP+OP or DAD were shown to have a poor prognosis.

Analysis of the clinical features of antisynthetase syndrome: a retrospective cohort study in China

OBJECTIVE

To summarize the clinical, serological, and radiological characteristics of anti-synthetase syndrome (ASS) patients with different anti-aminoacyl-tRNA synthase antibody.

METHODS

Retrospective analysis was performed based on the clinical data of 88 patients diagnosed with ASS in Tianjin Medical University General Hospital from January 2015 to December 2020. The clinical data included general conditions, serological indexes, high-resolution CT (HRCT) characteristics, and pulmonary function manifestations.

RESULTS

Among the 88 patients, there were 17 males and 71 females. The anti-synthetase antibodies included anti-Jo-1 (n = 42), anti-PL-7 (n = 14), anti-PL-12 (n = 9), anti-EJ (n = 20), and anti-OJ (n = 3) antibodies. The most common clinical manifestations of ASS patients were interstitial lung disease (ILD) (90%, 79/88), followed by myositis (79.5%, 70/88), arthritis (50%, 44/88), and rash (50%, 44/88). The frequency of arthritis in the anti-Jo-1 antibody-positive group was higher than that of the anti-PL-7 and anti-EJ antibody groups (P = 0.004, P = 0.002, respectively). The frequency of Gottron's sign in the anti-PL-7 antibody positive group was higher than that of the anti-Jo-1 and anti-PL-12 antibody-positive groups (P = 0.006, P = 0.04). Isolated arthritis was the most frequent initial symptoms in anti-Jo-1 antibody-positive group (47.6%, 20/42), while isolated ILD was most frequent in patients with anti-EJ antibody (50%, 10/20), and isolated myositis in patients carrying anti-OJ (66.7%, 2/3). There were only 32 cases (36.4%) with the typical clinical triad (myositis, arthritis, ILD). In our cohort, 79 patients (90%) were complicated with ILD. Meanwhile, 7 out of 79 cases were classified into rapid progressive group with 6 cases (85.7%) carrying anti-Ro-52 antibody. The probability of reticular and honeycombing shadow in HRCT of patients with anti-EJ antibody positive was higher than that of other groups (P < 0.05).

CONCLUSION

ILD, myositis, and arthritis were the most common clinical manifestations in patients with ASS. Different antibody-positive patients have different initial symptoms. Patients with isolated arthritis, myositis, and ILD should be vigilant of ASS. The complication of anti-Ro-52 antibody in ASS patients was associated with rapidly progressive pulmonary interstitial disease. Patients with positive anti-EJ antibodies tend to have ILD as the first symptom, and with high occurrence of ILD, the HRCT showed more serious patterns, suggesting the correlation between anti-EJ antibodies and ILD. Key Points • Analyzing specific clinical manifestations in ASS patients with different ARS antibodies can raise awareness of the disease and reduce misdiagnosis. • Anti-EJ antibodies were correlated with ILD. • Anti-Ro-52 antibodies may correlate with RP-ILD in ASS patients.

Risk Factors and Predictive Model for Dermatomyositis Associated with Rapidly Progressive Interstitial Lung Disease

Background

Rapidly progressive interstitial lung disease (RP-ILD) is a significant complication that determines the prognosis of dermatomyositis (DM). Early RP-ILD diagnosis can improve screening and diagnostic efficiency and provide meaningful guidance to carry out early and aggressive treatment.

Methods

A retrospective screening of 284 patients with DM was performed. Clinical and laboratory characteristics of the patients were recorded. The risk factors of RP-ILD in DM patients were screened by logistic regression (LR) and machine learning methods, and the prediction models of RP-ILD were developed by machine learning methods, namely least absolute shrinkage and selection operator (LASSO), random forest (RF), and extreme gradient boosting (XGBoost).

Results

According to the result of univariate LR, disease duration is a protective factor for RP-ILD, and ESR, CRP, anti-Ro-52 antibody and anti-MDA5 antibody are risk factors for RP-ILD. The top 10 important variables of the 3 machine learning models were intersected to obtain common important variables, and there were 5 common important variables, namely disease duration, LDH, CRP, anti-Ro-52 antibody and anti-MDA5 antibody. The AUC of LASSO, RF and XGBoost test set were 0.661, 0.667 and 0.867, respectively. We further validated the performance of these three models on validation set, and the results showed that, the AUC of LASSO, RF and XGBoost were 0.764, 0.727 and 0.909, respectively. Based on the results of the models, XGBoost is the optimal model in this study.

Conclusion

Disease duration, LDH, CRP, anti-Ro-52 antibody and anti-MDA5 antibody are vital risk factors for RP-ILD in DM. The prediction model constructed using XGBoost can be used for risk identification and early intervention in DM patients with RP-ILD and practical application.

Anti-Ro52-positive antisynthetase syndrome (ASS): a case report and review of the literature

Background

This study aimed to diagnose and treat a patient with anti-Ro52-positive antisynthetase syndrome (ASS), investigate the association between anti-Ro52 antibodies and ASS, and determine its clinical significance. The objective of this clinical report is to highlight this unusual syndrome to avoid incorrect diagnosis.

Case Description

A middle-aged woman presenting with obvious lung symptoms was admitted to our hospital. A physical examination revealed swollen joints in both hands, mechanic's hands, and normal muscle strength and muscle tone in all 4 extremities. A myositis-specific antibody panel, lung computed tomographic (CT) imaging, electromyography, and muscle biopsy were performed as auxiliary examinations, and appropriate treatment was administered after the confirmed diagnosis. The myositis-specific antibody panel yielded strongly positive results for anti-Jo-1 and anti-Ro52 antibodies, lung CT imaging revealed interstitial lung disease, electromyography revealed myogenic damage, and muscle magnetic resonance imaging revealed multiple inflammatory exudates. A definitive diagnosis of ASS was made, and glucocorticoid and immunosuppressant therapy were administered. After treatment, the patient's symptoms were alleviated, creatine kinase activity was reduced, and signs of disease activity and secondary tumors were not observed on a subsequent follow-up evaluation.

Conclusions

Anti-Ro52 antibodies, being myositis-associated antibodies, can lead to an atypical clinical presentation in ASS patients and are potentially associated with a poor prognosis. Therefore, thorough follow-up evaluation is required for such cases.

Polymyositis: does it really exist as a distinct clinical subset?

PURPOSE OF REVIEW

To summarize information on polymyositis; diagnosis, definitions, published data and opinions.

RECENT FINDINGS

Polymyositis originally referred to inflammatory muscle diseases presenting with muscle weakness and inflammatory cell infiltrates on muscle tissue visible by microscopy. Over time and with improved technology to immunophenotype infiltrating inflammatory cells and characterize muscle fibres, the meaning of polymyositis changed and became more specific. There is ongoing controversy over the term polymyositis, with proponents for a strict definition based on histopathological and immunohistochemical features on muscle biopsies whereas others advocate for a broader clinical and histopathological phenotype. Over the past decades, the discovery of several myositis-specific autoantibodies together with distinct histopathological features have enabled the identification of new subsets previously labelled as polymyositis notably the antisynthetase syndrome and the immune-mediated necrotizing myopathies thus reducing the number of patients classified as polymyositis.

SUMMARY

There are still a small number of patients among the idiopathic inflammatory myopathies that can be classified as polymyositis as discussed in this review but the entity is now considered relatively rare.